Some critical qualitative details of lorica construction in the type species of Calliacantha Leadbeater (Choanoflagellata)

Abstract

Qualitative structural details, amplifying or correcting previous accounts in the literature on this species were compiled using light microscopy and/or EM of dry whole mounts, prepared in situ from freshly gathered wild material mainly from temperate sources in Denmark, Britain and South Alaska [USA]. The more important findings were summarized diagrammatically. These included elaborate and constant details of assembly at the anterior end of the lorica, combined with much greater variability at the hind end. The absence of continuity between the 3 anterior spines and any of the 6 longitudinal costae present at the front end of the lorica chamber was confirmed, but a range of conditions involving numerical reduction in costal numbers at the hind end was illustrated. The overall size range encountered in the 3 temperate localities listed was illustrated photographically, but the large cells characteristic of Arctic sources were represented, for a qualitative purpose only, by means of a single photograph recording a specimen collected beneath sea ice in North Alaska.